code: def test_gradcheck(self, device):
      if "cuda" in str(device):
          pytest.skip(
              "RuntimeError: Backward is not reentrant, i.e., running backward,"
          )
      batch_size, channels, height, width = 1, 1, 3, 4
      img = torch.rand(
          batch_size, channels, height, width, device=device
      )
      img = tensor_to_gradcheck_var(img)
      self.gradcheck(canny, img)
  
file_path: kornia/test/filters/test_canny.py
imports: import pytest
  import torch
  from kornia.filters import Canny, canny
  from kornia.testing import BaseTester, tensor_to_gradcheck_var
  from kornia.utils._compat import torch_version
label_desc: Use image node_id 9 for calling the TestCanny obj's underlying member method code with example usage: obj.test_gradcheck(device) without return types